The
overarching question, How do we know what we know? is vital to
being a critical thinker, citizen, and scientist. It is a particularly
important "lens" to use today when we are awash in information from
a virtually unlimited variety of sources. Scientists rely on evidence
(data from their own and others' observations and investigations) to
construct explanations and answer their questions. A good scientist
respects evidence and is willing to change his or her ideas, predictions,
theories, and explanations if new information is inconsistent or contradictory.